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Muon g − 2 with SU(2)L multiplets
Takaaki Nomura, Hiroshi Okada
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We propose a simple model to obtain sizable muon anomalous magnetic dipole moment (muon \begin{document}$ g-2 $\end{document}) introducing several \begin{document}$ S U(2)_L $\end{document} multiplet fields without any additional symmetries. The neutrino mass matrix is simply induced via type-II seesaw scenario in terms of \begin{document}$ S U(2)_L $\end{document} triplet Higgs with \begin{document}$ U(1)_Y $\end{document} hypercharge 1. In addition, we introduce an \begin{document}$ S U(2)_L $\end{document} quartet vector-like fermion with \begin{document}$ 1/2 $\end{document} hypercharge and scalar with \begin{document}$ 3/2 $\end{document} hypercharge. The quartet fermion plays a crucial role in explaining muon \begin{document}$ g-2 $\end{document} causing the chiral flip inside a loop diagram with mixing between triplet and quartet scalar bosons via the standard model Higgs. We show numerical analysis and search for allowed region in our parameter space, and demonstrate the collider physics.
Symmetry energy effect on hot nuclear matter and proto-neutron stars
Xuhao Wu, Peng-Cheng Chu, Min Ju, He Liu
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We examine the effects of symmetry energy on proto-neutron stars (PNSs) by employing equation of state (EOS) described by the relativistic mean-field (RMF) model. The thermal properties of dense matter and the bulk properties of PNSs are investigated under the assumptions of isothermy, isentropy, and fixed lepton fractions. The polytropic index is calculated at finite temperature, revealing a negative correlation with the PNS maximum mass that the EOS can support. The properties of PNSs during the heating and cooling stages along their evolution line are explored under different combinations of lepton fraction and entropy. We investigate the correlation between the symmetry energy slope L and the properties of PNSs. As L increases, the PNS radius also increases; however, this effect diminishes with a growing lepton fraction for the isentropic case. These results indicate that the nuclear symmetry energy and its density dependence play crucial roles in determining the properties of PNSs and their evolution stages.
Exploring percolation phase transition in the three-dimensional Ising model with machine learning
Ranran Guo, Xiaobing Li, Rui Wang, Shiyang Chen, Yuanfang Wu, Zhiming Li
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The percolation study offers valuable insights into the characteristics of phase transition, shedding light on the underlying mechanisms that govern the formation of global connectivity within the system. We explore the percolation phase transition in the 3D cubic Ising model by employing two machine learning techniques. Our results demonstrate the capability of machine learning methods in distinguishing different phases during the percolation transition. Through the finite-size scaling analysis on the output of the neural networks, the percolation temperature and a correlation length exponent in the geometrical percolation transition are extracted and compared to those in the thermal magnetization phase transition within the 3D Ising model. These findings provide a valuable way essential for enhancing our understanding of the property of the QCD critical point, which belongs to the same universality class as the 3D Ising model.
Fixing the AdS3 metric from the pure state entanglement entropies of CFT2
Peng Wang, Houwen Wu, Haitang Yang
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In this paper, based on RT formula, by identifying the pure state UV and IR entanglement entropies of a perturbed CFT2 with geodesic lengths in the bulk, we demonstrate that the dual geometry is uniquely determined to be asymptotically AdS3. The pure AdS3 geometry is recovered by taking the massless limit of the system. Our derivations hold in both static and covariant scenarios.
R2 corrections to holographic heavy quarkonium dissociation
Zhou-Run Zhu, Manman Sun, Rui Zhou, Jinzhong Han
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In this paper, we investigate the \begin{document}$R^2$\end{document} corrections to the dissociation of heavy quarkonium in the Gauss-Bonnet gravitational background. We analyze the impact of Gauss-Bonnet parameter \begin{document}$\lambda_{GB}$\end{document} on the spectral function of charmonium and bottomonium, and examine how \begin{document}$\lambda_{GB}$\end{document} affects the dissociation of heavy quarkonium. Our results show that \begin{document}$\lambda_{GB}$\end{document} reduces the peak height and increases the peak width of the spectral function, suggesting that \begin{document}$\lambda_{GB}$\end{document} enhances the dissociation of heavy quarkonium. We also discuss how the dissociation of heavy quarkonium varies with the ratio of shear viscosity to entropy density and find the dissociation will be easier in more perfect plasma. Additionally, we observe that the temperature decreases the peak height and widens the peak, thereby accelerating the dissociation.
Effects of nuclear deformation and surface polarization on proton-emission half-lives
Hanlin Wang, Zhen Wang, Dong Bai, Dongdong Ni, Zhongzhou Ren
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Proton radioactivity is known as an important method to investigate the characteristics of unstable neutron-deficient nuclei beyond the proton dripline. Based on the tunneling of one proton through the potential barrier formed by Woods-Saxon plus expanded Coulomb potentials, the half-lives of various proton emitters are calculated using distorted wave Born approximations. Particularly, deformation and nuclear surface polarization are considered in our calculation, and their effects on proton-emission half-lives are researched. An analytic relationship of spectroscopic factors with deformation and polarization is proposed as well, which significantly reduces the deviations of calculated half-lives from experimental data. Moreover, inspired by the newly experimental results for the first proton emitter discovered \begin{document}$ ^{53}\text{Co}^m $\end{document} [L. G. Sarmiento, et al., Nat. Commun. 14, 5961 (2023)], we calculate its two proton-emission branches and well interpret the partial half-lives. It is noteworthy that this high-spin isomer has some particular characteristics including diminutive spectroscopic factors and stronger daughter-proton interactions, which considerably enhance the effects of deformation and polarization.
Analysis of the $K^- p \to \gamma \Lambda$ reaction
Yi Pan, Rong Li, Bo-Chao Liu
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In this work, we study the \begin{document}$K^- p \to \gamma \Lambda$\end{document} reaction in an effective Lagrangian approach and isobar model. Compared to previous studies using an Regge-plus-resonance model, here we consider the contributions of the t-channel(K and \begin{document}$K^*$\end{document}) and u-channel(proton) exchanges explicitly as the background contribution. To restore the gauge invariance of the amplitude violated by introducing the phenomenological form factors, we employ two different methods that adopted in literatures. Then we discuss the roles of possible resonance contributions in this reaction and present the predictions of Λ polarization based on various models. We find that the contribution of the background terms play an important role in the present reaction. On the other hand, the \begin{document}$\Lambda(1520)$\end{document}, \begin{document}$\Sigma(1660)$\end{document} and \begin{document}$\Sigma(1670)$\end{document} resonances may also contribute in this reaction. Due to the uncertainties of the present data and the relatively small contributions of the hyperon resonances, we can not identify the roles of various hyperon resonances in the present work. While, we show that the measurement of the spin polarization of the final Λ will be helpful to verify various models.
Anisotropic flow, flow fluctuation and flow decorrelation in relativistic heavy-ion collisions: the roles of sub-nucleon structure and shear viscosity
Jie Zhu, Xiang-Yu Wu, Guang-You Qin
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We study the transverse momentum (\begin{document}$p_T$\end{document}) differential anisotropic flow and flow fluctuation in Pb+Pb collisions at \begin{document}$\sqrt{s_{NN}}$\end{document}=5.02 TeV at the LHC. A (3+1)-dimensional CLVisc hydrodynamics framework with fluctuating TRENTO (or AMPT) initial conditions is utilized to simulate the space-time evolution of the quark-gluon plasma (QGP) medium. The effects of shear viscosity and the sub-nucleon structure on anisotropic flow and flow fluctuation are analyzed. Our result shows that shear viscosity tends to suppress both flow coefficients (\begin{document}${v_2\{2}\}$\end{document}, \begin{document}${v_2\{4\}}$\end{document}, \begin{document}${\langle v_2\rangle}$\end{document}) and flow fluctuation (\begin{document}${\sigma_{v_2}}$\end{document}) due to its smearing effect on local density fluctuation. The flow coefficients appear to be insensitive to the sub-nucleon structure, whereas for flow fluctuation \begin{document}${\sigma_{v_2}}$\end{document}, it tends to be suppressed by the sub-nucleon structure in central collisions but enhanced in peripheral collisions. After taking into account the sub-nucleon structure effect, our numerical result can qualitatively describe the relative flow fluctuations (\begin{document}${v_2\{4\}/v_2\{2\}}$\end{document}, \begin{document}$F({v_2})$\end{document}) measured by the ALICE Collaboration at the LHC. We further investigate the effects of shear viscosity, sub-nucleon structure and initial condition model on the flow angle and flow magnitude decorrelations (\begin{document}${A_2^f}$\end{document}, \begin{document}${M_2^f}$\end{document}) using the four-particle correlation method. We find that the flow decorrelation effect is typically stronger in central collisions than in peripheral collisions. The flow angle decorrelation is found to be insensitive to the shear viscosity and sub-nucleon structure, whereas the flow magnitude decorrelation shows quite different behavior when using TRENTO or AMPT initial condition model. Our study sheds light on the anisotropic flow, transport properties and initial structure of the QGP created in high-energy nuclear collisions.
Impact of quadrupole and hexadecapole deformations and associated orientations on a variety of asymmetric nuclear reactions
Diksha, Harshit Sharma, Manoj K. Sharma
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The present manuscript investigates the fusion-ER cross-sections for different projectile-target combinations, 16O + 148,150Nd, 165Ho, 194Pt, 18O+ 148Nd, 194Pt, 192Os, 19F + 188Os and \begin{document}$ ^{30}Si $\end{document} + \begin{document}$ ^{170}Er $\end{document} consisting of quadrupole (\begin{document}$ \beta_2 $\end{document}) and hexadecapole (\begin{document}$ \beta_4 $\end{document}) deformed target nuclei. The study analyzes the influence of higher-order deformations and corresponding orientation criterias adopted for the exploration of the dynamics of the considered nuclei. The influence of these parameters has been studied in terms of capture cross-section (\begin{document}$ \sigma_{cap} $\end{document}), Compound nucleus (CN) formation probability (\begin{document}$ P_{CN} $\end{document}), survival probability (\begin{document}$ W_{sur} $\end{document}), and the fusion-ER cross-sections across the center of mass energies (\begin{document}$ E_{c.m.} $\end{document}). The study recognizes the importance of the fission barrier in determining the survival probability (\begin{document}$ W_{sur} $\end{document}) of the compound nucleus and subsequently the ER cross-sections. A discrepancy among the calculated and experimental ER cross-sections is observed, particularly in reactions with lower fission barriers. In the reactions with a lower fission barrier of formed CN, the level density parameter ratio (\begin{document}$ a_f/a_n $\end{document}) for the fission and neutron-evaporation channels helps to address the experimental data.
Cosmological perturbations in the energy-momentum squared gravity theory: constraints from gravitational wave standard sirens and redshift space distortions
Qi-Ming Fu, Xin Zhang
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We investigate the linear cosmological perturbations in the context of the so-called energy-momentum squared gravity (EMSG) theory. Recent researches show that the EMSG theory can reproduce viable background cosmological evolution comparable to ΛCDM, while the matter-dominated era exhibits slight distinctions. In this paper, we mainly focus on the power-law EMSG models and derive the equations for the linear cosmological perturbations. We explore the propagation of the gravitational wave (GW) and the growth of matter density perturbation at the first order, and estimate the model parameters from the simulated GW data and the observed redshift space distortion data. Our analysis reveals that the model parameters should be small and positive in \begin{document}$ 1\sigma $\end{document} confidence interval, which indicates that the theory is in good agreement with the observational data and can be regarded as an alternative for the standard cosmological model.
Application of the Woods-Saxon potential in studying quadrupole and octupole excited states using machine learning
Hadi Sobhani, Yan-An Luo
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In this study, the energy bands of quadrupole and octupole excited states are investigated. This is achieved by employing the Bohr Hamiltonian, incorporating quadrupole and octupole deformations whose variables are accurately separated. Subsequently, the Woods-Saxon potential is added to the problem. Given that this problem cannot yield suitable solutions using conventional approximations, we solve it numerically using machine learning. A detailed description is given of how wave functions and their associated energies are obtained. It is demonstrated throughout this procedure how machine learning helps us and makes it easier to accomplish our objective. We have examined and analyzed the energy spectrum and possible multipole transitions for candidate isotopes \begin{document}$ ^{226} $\end{document}Ra and \begin{document}$ ^{226} $\end{document}Th.
One-loop analytical expressions for gg/γγϕiϕj in Higgs Extensions of the Standard Models and its applications
Khiem Hong Phan, Dzung Tri Tran, Thanh Huy Nguyen
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General one-loop formulas for loop-induced processes \begin{document}$gg/\gamma \gamma \rightarrow \phi_i\phi_j$\end{document} with \begin{document}$\phi_i\phi_j = hh,~hH,~HH$\end{document} are presented in the paper. Analytic expressions evaluated in this work are valid for a class of Higgs Extensions of the Standard Models, e.g. Inert Doublet Higgs Models, Two Higgs Doublet Models, Zee-Babu Models as well as Triplet Higgs Models, etc. Analytic expressions for one-loop form factors are written in terms of the basic scalar one-loop two-, three- and four-point functions following the output format of both the packages \begin{document}$ {\tt LoopTools}$\end{document} and \begin{document}$ {\tt Collier}$\end{document}. Physical results can be hence evaluated numerically by using one of the mentioned packages. Analytic results are tested by several checks such as the ultraviolet finiteness, infrared finiteness of the one-loop amplitudes. Furthermore, the amplitudes also obey the ward identity due to massless gauge bosons in the initial states. This identity is also verified numerically in this work. In the applications, we present the phenomenological results for the investigated processes in the Zee-Babu model as a typical example in this report. In particular, production cross-section for the processes \begin{document}$\gamma \gamma\rightarrow hh$\end{document} are scanned over the parameter space of the Zee-Babu Models.
Reaction rate of the radiative p12C capture in the modified potential cluster model
S. B. Dubovichenko, N. A. Burkova, A. S. Tkachenko, A. Samratova
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The astrophysical S-factor of the 12C(p,γ0)13N reaction at energies from 25 keV to 5 MeV within the framework of a modified potential cluster model with forbidden states is considered. The experimental phase shifts resonant \begin{document}$ {\delta _{^2{S_{1/2}}}} $\end{document}, \begin{document}$ {\delta _{^2{P_{3/2}}}} $\end{document}, and non-resonant \begin{document}$ {\delta _{^2{D_{3/2}}}} $\end{document}at the energies up to Ec.m. =3 MeV are reproduced with high accuracy, which provides the appropriate agreement with the experimental data for the S-factor of 1950 -2023 years. Two sets of asymptotic constant are used: Set I refers to Cw = 1.30(2), and Set II refers to Cw = 1.37(1). Set I leads to the astrophysical factor S(25) = 1.34 ± 0.02 keV·b, which is in agreement with data by Skowronski et al., 2023 – 1.34 ± 0.09 keV·b; Set II gives S(25) = 1.49 ± 0.02 keV·b, which is in agreement with data by Kettner et al., 2023 – 1.48 ± 0.09 keV·b. The reaction rates of 12C(p,γ0)13N at temperatures T9 from 0.001 to 10 are calculated. The detailed comparison with some models, the R-matrix approach, and NACRE II data for reaction rates is considered.
Predictions for the synthesis of new superheavy nuclei with 252Cf target
Ming-Hao Zhang, Ying Zou, Mei-Chen Wang, Qing-Lin Niu, Gen Zhang, Feng-Shou Zhang
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The \begin{document}$ ^{252} {\rm{Cf}}$\end{document} isotope produced at Oak Ridge National Laboratory is a promising target material for the synthesis of new superheavy nuclei through fusion reaction experiments. Within the framework of the dinuclear system model, the reaction systems with the \begin{document}$ ^{252} {\rm{Cf}}$\end{document} target and the \begin{document}$ ^{48} {\rm{Ca}}$\end{document}, \begin{document}$ ^{45} {\rm{Sc}}$\end{document}, \begin{document}$ ^{50} {\rm{Ti}}$\end{document}, \begin{document}$ ^{51} {\rm{V}}$\end{document}, \begin{document}$ ^{54} {\rm{Cr}}$\end{document}, \begin{document}$ ^{55} {\rm{Mn}}$\end{document} projectiles are investigated for the synthesis of new isotopes \begin{document}$ ^{295-297} {\rm{Og}}$\end{document}, \begin{document}$ ^{292-294} {\rm{119}}$\end{document}, \begin{document}$ ^{297-299} {\rm{120}}$\end{document}, \begin{document}$ ^{298-300} {\rm{121}}$\end{document}, \begin{document}$ ^{301-303} {\rm{122}}$\end{document} and \begin{document}$ ^{302-304} {\rm{123}}$\end{document}. The decreasing trend of the maximal evaporation residue cross sections with the increasing proton number of the compound nucleus are discussed in the capture, fusion and survival stages. Additionally, the radioactive beam-induced reactions based on the \begin{document}$ ^{252} {\rm{Cf}}$\end{document} target are investigated to reach the predicted neutron shell closure N = 184, with the maximal evaporation residue cross section predicted to be 21 fb for synthesizing \begin{document}$ ^{302} {\rm{Og}}$\end{document}. The predicted results fall below the current detection limitation, indicating the necessity for advancement in both accelerator and detection techniques, as well as exploration of alternative reaction mechanisms.
Off-equatorial deflections and gravitational lensing. II. In general stationary and axisymmetric spacetimes
Xinguang Ying, Junji Jia
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In this work, we develop a general perturbative procedure to find the off-equatorial plane deflections in the weak deflection limit in general stationary and axisymmetric spacetimes, allowing the existence of the generalized Carter constant. Deflections of both null and timelike rays, with the finite distance effect of the source and detector taken into account, are obtained as dual series of \begin{document}$M/r_0$\end{document} and \begin{document}$r_0/r_{s,d}$\end{document}. These deflections allow a set of exact gravitational lensing equations from which the images' apparent angular positions are solved. The method and general results are then applied to the Kerr-Newmann, Kerr-Sen, and rotating Simpson-Visser spacetimes to study the effect of the spin and characteristic (effective) charge of the spacetimes and the source altitude on the deflection angles and image apparent angles. It is found that, in general, both the spacetime spin and charge only affect the deflections from the second non-trivial order, while the source altitude influences the deflection from the leading order. Because of this, it is found that, in gravitational lensing in realistic situations, it is hard to measure the effects of the spacetime spin and charge from the images' apparent locations. We also presented the off-equatorial deflections in the rotating Bardeen, Hayward, Ghosh, and Tinchev black hole spacetimes.
Critical collapse in asymptotically anti-de Sitter spacetime
Li-Jie Xin, Cheng-Gang Shao
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We investigate the critical collapse of spherically symmetric scalar fields in asymptotically anti-de Sitter spacetime, focusing on two scenarios: real and complex scalar fields with potentials. By fine-tuning the amplitude of the initial scalar field under different cosmological constants, we find a linear relationship between the critical amplitude of the first collapse and the cosmological constant in both scenarios. Furthermore, we observe that the slope of this linear relationship varies linearly with the coupling strength.
Bremsstrahlung emission from nucleon-nucleus reactions in dense medium of compact stars
Sergei P. Maydanyuk, Ju-Jun Xie, Kostiantyn A. Shaulskyi
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Bremsstrahlung photons emitted during nucleon-nucleus reactions in compact star are investigated. Influence of density of stellar medium on intensity of emission is studied at first time in quantum approach. Bremsstrahlung model is generalized, where new term describing influence of stellar medium is added to interactions between nucleons of nucleus (in frameworks of nuclear model of deformed oscillatoric shells). Polytropic EOS, Chandrasekar EOS and Harrison-Wheeler EOS are applied for calculations. Unified EOS of neutron-star matter of Haensel and Potekhin based on FPS an SLy EOSs is used for tests. Bremsstrahlung calculations are tested on existed measurements of bremsstrahlung in the scattering of protons off the 197Au nuclei at energy of proton beam of \begin{document}$ E_{\rm p}=190 $\end{document} MeV. Many properties of bremsstrahlung emitted from nuclear processes in stellar medium of compact stars are studied at first time. In particular, the spectra of photons in the scattering of protons and neutrons off 4He, 8Be, 12C, 16O, 24Mg, 40Ca, 56Fe are estimated in dependence on density of stellar medium. Medium of white dwarfs has small influence on the bremsstrahlung emission from nuclear processes, while bremsstrahlung emission is intensive in neutron stars and it is changed essentially in dependence on stellar density and structure.
Off-equatorial deflections and gravitational lensing. I. In Kerr spacetime and effect of spin
Tingyuan Jiang, Xiaoge Xu, Junji Jia
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This paper investigates off-equatorial plane deflections and gravitational lensing of both null signals and massive particles in Kerr spacetime in the weak deflection limit, with the finite distance effect of the source and detector taken into account. This is the effect caused by the fact that both the source and detector are located at finite distances from the lens, while many researchers often use the deflection angle for infinite distances from sources and detectors. The deflection in both the \begin{document}$ \phi $\end{document} and \begin{document}$ \theta $\end{document} directions is computed as power series of \begin{document}$ M/r_0 $\end{document} and \begin{document}$ r_0/r_{\mathrm{s,d}} $\end{document}, where \begin{document}$ M,\,r_{\mathrm{s,d}} $\end{document} are the spacetime mass and source and detector radii respectively, and \begin{document}$ r_0 $\end{document} is the minimal radial coordinate of the trajectory. The coefficients of these series are simple trigonometric functions of \begin{document}$ \theta_ \mathrm{e} $\end{document}, the extreme value of the \begin{document}$ \theta $\end{document} coordinate of the trajectory. A set of exact gravitational lensing equations is used to solve for \begin{document}$ r_0 $\end{document} and \begin{document}$ \theta_ \mathrm{e} $\end{document} for given deviation angles \begin{document}$ \delta\theta $\end{document} and \begin{document}$ \delta\phi $\end{document} of the source, and two lensed images are always obtained. The apparent angles and their magnifications of these images, and the time delays between them are solved and their dependence on various parameters, especially spacetime spin \begin{document}$ \hat{a} $\end{document} are analyzed in great detail. It is found that there generally exist two critical spacetime spin values that separate the case of test particles reaching the detector from different sides of the \begin{document}$ z $\end{document} axis from the cases in which the images appear from the same side in the celestial plane. Three potential applications of these results are discussed.
Sub-barrier Fusion Cross Sections: Role of Pauli Blocking and Isospin Asymmetry
Weiwen Deng, Kaixuan Cheng, Chang Xu
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Heavy-ion fusion reaction is relevant to a number of important issues not only in stellar environment but also in the synthesis of new nuclides and superheavy elements. In this work, the role of Pauli blocking and isospin effect in sub-barrier fusion reactions is investigated within the well established coupled-channels method. An isospin-dependent Pauli blocking potential is proposed to better address the deep sub-barrier fusion hindrance problem. It is found that the Pauli blocking effect manifests itself strongly for isospin symmetric targets and is reduced for targets with large isospin asymmetries. The agreement between experimental and theoretical fusion cross sections is improved for both 12C-target and 16O-target systems.
Search for the lepton number violation decay ϕπ+π+ee via J/ψϕη
M. Ablikim, M. N. Achasov, P. Adlarson, O. Afedulidis, X. C. Ai, R. Aliberti, A. Amoroso, M. R. An, Q. An, Y. Bai, O. Bakina, I. Balossino, Y. Ban, H.-R. Bao, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, J. F. Chang, G. R. Che, Y. Z. Che, G. Chelkov, C. Chen, Chao Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, S. L. Chen, S. M. Chen, T. Chen, X. R. Chen, X. T. Chen, Y. B. Chen, Y. Q. Chen, Z. J. Chen, Z. Y. Chen, S. K. Choi, G. Cibinetto, S. C. Coen, F. Cossio, J. J. Cui, H. L. Dai, J. P. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, B. Ding, X. X. Ding, Y. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, M. C. Du, S. X. Du, Z. H. Duan, P. Egorov, Y. H. Fan, J. Fang, S. S. Fang, W. X. Fang, Y. Fang, Y. Q. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. F
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Using \begin{document}$ (1.0087\pm0.0044)\times10^{10} $\end{document} \begin{document}$ J/\psi $\end{document} events collected by the BESIII detector at the BEPCII collider, we search for the lepton number violation decay \begin{document}$ \phi \to \pi^+ \pi^+ e^- e^- $\end{document} via \begin{document}$ J/\psi\to \phi\eta $\end{document}. No signal is found and the upper limit on the branching fraction of \begin{document}$ \phi \to \pi^+ \pi^+ e^- e^- $\end{document} is set to be \begin{document}$ 1.3\times10^{-5} $\end{document} at the 90% confidence level.
Effective Potential and Topological Photon Spheres: A Novel Approach to Black Hole Parameter Classification
Mohammad Ali S. Afshar, Jafar Sadeghi
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In this paper, we base our analysis on the assumption that the existence of a photon sphere is an intrinsic feature of any ultra-compact gravitational structure with spherical symmetry. Utilizing the concept of a topological photon sphere, we categorize the behaviors of various gravitational models based on the structure of their photon spheres. This innovative approach enables us to define boundaries for black hole parameters, subsequently allowing us to classify the model as either a black hole or a naked singularity. Indeed, we will demonstrate that the presence of this interplay between the gravitational structure and the existence of a photon sphere is a unique advantage that can be utilized from both perspectives. Our observations indicate that a gravitational model typically exhibits the behavior of a horizonless structure (or a naked singularity) when a minimum effective potential (a stable photon sphere) appears within the studied spacetime region. Additionally, in this study, we tried to investigate the effect of this structure on the behavior of the photon sphere by choosing models that are affected by the Perfect Fluid Dark Matter (PFDM). Finally, by analyzing a model with multiple event horizons, we show that the proposed method remains applicable even in such scenarios.
Investigation of heavy particle radioactivity and spontaneous fission of even Z superheavy nuclei
Kirandeep Sandhu, Gurjit Kaur, Manoj K. Sharma
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The Preformed Cluster Model (PCM) is applied to investigate the heavy particle radioactivity (HPR) and spontaneous fission (SF) processes for even-Z superheavy nuclear systems. Different proximity potentials are used to calculate decay half-lives of Z=112-120 nuclei. The fragmentation potential and preformation distribution suggest that spontaneous fission is the major contributor upto Z=114 and HPR starts competing for heavier nuclei. The heavy cluster emission is supported by Pb-magicity whereas SF is reinforced due to the deformations of fission fragments. The heavy cluster decay half-lives (Log\begin{document}$ _{10} $\end{document}TC) are calculated using PCM and are compared with the estimates of Analytical Super Asymmetric Fission (ASAF) Model. The calculated Log\begin{document}$ _{10} $\end{document}TC show nice agreement with the ASAF measurements for the use of Prox-00 and Mod Prox-00 versions of potentials. However, Prox-77, Prox-88, and Prox-BW-91 are not appropriate to address the Log\begin{document}$ _{10} $\end{document}TC for Z\begin{document}$ \geq $\end{document}116 nuclei. In order to resolve this, Z-dependence in the radius parameters is included. Interestingly, half-lives match the ASAF data after the inclusion of Z-dependence. The branching ratios are also calculated for superheavy nuclei and compared with the estimates of Unified description (UD) formula, Universal (UNIV) curve, Universal decay law (UDL), Horoi formula and ASAF measurements. Further, the spontaneous fission half-lives (\begin{document}$ T_{SF} $\end{document}) of \begin{document}$ ^{282} $\end{document}Cn, \begin{document}$ ^{284} $\end{document}Cn, \begin{document}$ ^{284} $\end{document}Fl and \begin{document}$ ^{286} $\end{document}Fl superheavy nuclei are also estimated through various proximity potentials. Among all, Prox-00 is appropriate to address the experimental data nicely. Using same, the spontaneous fission half-lives are estimated through PCM for Z=116-120 isotopes at different neck-length parameters. Finally, the scaled total kinetic energy (TKE) values are compared nicely with the available data.
Probing Heavy Charged Higgs Boson Using Multivariate Technique at Gamma-Gamma Collider
Ijaz Ahmed, Abdul Quddus, Jamil Muhammad, Muhammad Shoaib, Saba Shafaq
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The current study explores the production of charged Higgs particles through photon-photon collisions within the context of the Two Higgs Doublet Model, including one-loop-level scattering amplitudes of Electroweak and QED radiation. The cross-section has been scanned for plane (\begin{document}$m_{\phi^{0}}, \sqrt{s}$\end{document}) investigating the process of \begin{document}$\gamma\gamma \rightarrow H^{+}H^{-}$\end{document}. Three particular numerical scenarios i.e., low-\begin{document}$m_{H}$\end{document}, non-alignment, and short-cascade are employed. The decay channels for charged Higgs particles are examined using \begin{document}$h^{0}$\end{document} for low-\begin{document}$m_{H^{0}}$\end{document} and \begin{document}$H^{0}$\end{document} for non-alignment and short-cascade scenario incorporating the new experimental and theoretical constraints along with the analysis for cross-sections. It reveals that at low energy, it is consistently higher for all scenarios. However, as \begin{document}$\sqrt{s}$\end{document} increases, it reaches a peak value at 1\begin{document}$~$\end{document}TeV for all benchmark scenarios. The branching ratio of the decay channels indicates that for non-alignment, the mode of decay \begin{document}$W^{\pm} h^{0}$\end{document} takes control, and for short cascade, the prominent decay mode remains \begin{document}$t\overline {b}$\end{document}, while in the low-\begin{document}$m_{H}$\end{document} the dominant decay channel is of \begin{document}$W^{\pm} h^{0}$\end{document}. In our research, we employ contemporary machine-learning methodologies to investigate the production of high-energy Higgs bosons within a 3.0 TeV \begin{document}$\gamma\gamma$\end{document} collider. We have used multivariate approaches such as Boosted Decision Trees (BDT), LikelihoodD, and Multilayer Perceptron (MLP) to show the observability of heavy-charged Higgs Bosons versus the most significant Standard Model backgrounds. The purity of the signal efficiency and background rejection are measured for each cut value.
Shadow and gravitational weak lensing around a quantum-corrected black hole surrounded by a plasma
Mirzabek Alloqulov, Yokubjon Isaqjonov, Sanjar Shaymatov, Abdul Jawad
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In this paper, we delve into the optical properties of a quantum-corrected black hole (BH) in loop quantum gravity, surrounded by a plasma medium. We first determine the photon and shadow radii resulting from quantum corrections and the plasma medium in the environment surrounding a quantum-corrected BH. We find that the photon sphere and the BH shadow radii decrease due to the quantum correction parameter α acting as a repulsive gravitational charge. We further delve into the gravitational weak lensing by applying the general formalism used to model the deflection angle of the light traveling around the quantum-corrected BH placed in the plasma medium. We show, in conjunction with the fact that the combined effects of the quantum correction and non-uniform plasma frequency parameter can decrease the deflection angle, that the light traveling through the uniform plasma can be strongly deflected compared to the non-uniform plasma environment surrounding the quantum-corrected BH. Finally, we consider the magnification of the lensed image brightness under the effect of the quantum correction parameter α, together with the uniform and non-uniform plasma effects.
Time-reversal invariance violation effect in dd scattering
M.N. Platonova, Yu.N. Uzikov
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Abstract:
A formalism has been developed for calculating the signal of violation of time-reversal invariance, provided that space-reflection (parity) invariance is conserved during the scattering of tensor-polarized deuterons on vector-polarized ones. The formalism is based on the Glauber theory with the full consideration of spin dependence of \begin{document}$ NN $\end{document} elastic scattering amplitudes and spin structure of colliding deuterons. The numerical calculations have been carried out in the range of laboratory proton energies of \begin{document}$ T_p = 0.1 $\end{document}–1.2 GeV using the SAID database for spin amplitudes and in the energy region of the SPD NICA experiment corresponding to the invariant mass of the interacting nucleon pairs \begin{document}$ \sqrt{s_{NN}} = 2.5 $\end{document}–25 GeV, using two phenomenological models of \begin{document}$ pN $\end{document} elastic scattering. It is found that only one type of the time-reversal non-invariant parity conserving \begin{document}$ NN $\end{document} interaction gives a non-zero contribution to the signal in question, that is important for isolating an unknown constant of this interaction from the corresponding data.
Friedmann’s Universe Controlled by Gauss-Bonnet Modified Gravity
F. dos Anjos, M. Novello
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Abstract:
We consider a Lagrangian to describe gravity using a nonlinear term depending on the Gauss-Bonnet invariant. We examine the conditions for a bouncing and the existence of an ulterior accelerated phase of the Universe.
Resonance of hypernuclei with complex momentum representation
Hantao Zhang, C.F. Chen, Xian-Rong Zhou, Zhongzhou Ren
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Abstract:
By combining the Skyrme-Hartree-Fock method with complex momentum representation (CMR), the resonant states of \begin{document}$ {}^{17}_\Lambda $\end{document}O, \begin{document}$ {}^{41}_{\Lambda} $\end{document}Ca, \begin{document}$ {}^{49}_{\Lambda} $\end{document}Ca, and \begin{document}$ {}^{57}_\Lambda $\end{document}Ni are investigated. The phase shifts for hyperon-nucleus elastic scattering are determined with continuum level density (CLD) and the scatting length as well as the resonance energy are obtained by utilizing the effective range expansion. Our method abbreviated as CMR-CLD exhibits good consistency with traditional approaches and provides some ground work for investigating scattering and resonance problems in deformed hypernuclei and multi-hyperon hypernuclei.
Coupled channel analysis of neutron transfer in 6,7Li induced reactions around the Coulomb barrier
Himanshu Sharma, Rishabh Kumar, Moumita Maiti
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Abstract:
The coupled reaction channel approach has proven to be quite effective in explaining the mechanism of nucleon transfer in heavy-ion reactions. Nevertheless, significant ambiguities remain regarding the selection of potential parameters and the states of the nuclei that should be coupled together for a specific reaction channel. We have analyzed the excitation functions for one- and two-neutron transfer in \begin{document}$ ^{6,7} $\end{document}Li-induced reactions on various targets using the coupled reaction channel formalism. Spectroscopic amplitudes are taken from existing literature and shell model calculations. The one-neutron transfer cross sections from \begin{document}$ ^{6} $\end{document}Li+\begin{document}$ ^{93} $\end{document}Nb and \begin{document}$ ^{7} $\end{document}Li+\begin{document}$ ^{115} $\end{document}In reactions are reasonably well reproduced by coupled reaction channel calculations. A reasonable match for the measured cross sections has also been obtained for the two-neutron transfer in \begin{document}$ ^{7} $\end{document}Li+\begin{document}$ ^{181} $\end{document}Ta reaction by employing the extreme cluster model.
Potential to Identify the Neutrino Mass Ordering with Reactor Antineutrinos in JUNO
Angel Abusleme, Thomas Adam, Shakeel Ahmad, Rizwan Ahmed, Sebastiano Aiello, Muhammad Akram, Abid Aleem, Fengpeng An, Qi An, Giuseppe Andronico, Nikolay Anfimov, Vito Antonelli, Tatiana Antoshkina, Burin Asavapibhop, João Pedro Athayde Marcondes de André, Didier Auguste, Weidong Bai, Nikita Balashov, Wander Baldini, Andrea Barresi, Davide Basilico, Eric Baussan, Marco Bellato, Marco Beretta, Antonio Bergnoli, Daniel Bick, Lukas Bieger, Svetlana Biktemerova, Thilo Birkenfeld, Iwan Blake, David Blum, Simon Blyth, Anastasia Bolshakova, Mathieu Bongrand, Clément Bordereau, Dominique Breton, Augusto Brigatti, Riccardo Brugnera, Riccardo Bruno, Antonio Budano, Jose Busto, Anatael Cabrera, Barbara Caccianiga, Hao Cai, Xiao Cai, Yanke Cai, Zhiyan Cai, Stéphane Callier, Antonio Cammi, Agustin Campeny, Chuanya Cao, Guofu Cao, Jun Cao, Rossella Caruso, Cédric Cerna, Vanessa Cerrone, Chi Chan, Jinfan Chang, Yun Chang, Auttakit Chatrabhuti, Chao Chen, Guoming Chen, Pingping Chen, Shaomin Chen, Yixue Chen, Yu Chen, Zh
Published:  
Abstract:
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment under construction in South of China. This paper presents an updated estimate of JUNO’s sensitivity to the neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants. This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and the neutrino mixing angle θ23. The sensitivity is obtained through a joint analysis of JUNO and TAO detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site, the local and global nuclear reactors, the JUNO and TAO detectors responses, the expected event rates and spectra of signal and backgrounds, and the systematic uncertainties of the analysis inputs. It is found that a 3σ median sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years × 26.6 GW thermal power.
Soft pattern of gravitational Rutherford scattering from heavy target mass expansion
Yu Jia, Jichen Pan, Jia-Yue Zhang
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Abstract:
We investigate the soft behavior of the tree-level Rutherford scattering processes mediated via t-channel one-graviton exchange. We consider two types of Rutherford scattering processes, e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in \begin{document}$ 1/M $\end{document} expansion, yet differ at the next-to-next-to-leading order, though some terms at this order still remain universal or depend on the target spin in a definite manner. The unpolarized cross sections in the second type are universal at the lowest order in projectile velocity expansion and through all orders in \begin{document}$ 1/M $\end{document}, independent of the spins of both projectile and target. The universality partially breaks down at relative order-\begin{document}$ v^2/M^2 $\end{document}, albeit some terms at this order still depend on the target spin in a specific manner.
Solving bound-state equations for scalar and hybrid QCD in two-dimensional spacetime
Xiaolin Li, Yu Jia, Ying Li, Zhewen Mo
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Abstract:
We investigate the bound-state equations in two-dimensional QCD in the \begin{document}$ N_c\to \infty $\end{document} limit. We consider two types of hadrons, an exotic "meson" (which is composed of a bosonic quark and a bosonic anti-quark), and an exotic "baryon" (composed of a fermionic quark and a bosonic antiquark). Using the Hamiltonian operator approach, we derive the corresponding bound-state equations for both types of hadrons from the perspectives of the light-front quantization and equal-time quantization, and confirm the known results. We also present a novel diagrammatic derivation for the exotic "meson" bound-state equation in the equal-time quantization. The bound-state equation for the exotic baryons in the equal-time quantization in two-dimensional QCD is new. We also numerically solve various bound-state equations, obtain the hadron spectrum and the bound-state wave functions of the lowest-lying states. We explicitly demonstrate the pattern that as the hadron is boosted to the infinite-momentum frame, the forward-moving bound-state wave function approaches the corresponding light-front wave function.
天体理论
Modified power law cosmology: theoretical scenarios and observational constraints
L.K. Sharma, Suresh Parekh, Saibal Ray, Anil Kumar Yadav, Maxim Khlopov, Kalyani C.K. Mehta
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Abstract:
This research paper examines a cosmological model in flat space-time via \begin{document}$ f(R,G) $\end{document} gravity where R and G are respectively the Ricci scalar and Gauss-Bonnet invariant. Our model assumes that \begin{document}$ f(R,G) $\end{document} is an exponential function of G combined with a linear combination of R. We scrutinize the observational limitations under a power law cosmology that relies on two parameters - \begin{document}$ H_0 $\end{document}, the Hubble constant, and q, the deceleration parameter, utilizing the 57-point \begin{document}$ H(z) $\end{document} data, 8-point BAO data, 1701-point Pantheon plus data, joint data of \begin{document}$ H(z) $\end{document} + Pantheon, and joint data of \begin{document}$ H(z) $\end{document} + BAO + Pantheon plus. The outcomes for \begin{document}$ H_0 $\end{document} and q are realistic within observational ranges. We have also addressed Energy Conditions, \begin{document}$ Om(z) $\end{document} analysis and cosmographical parameters like Jerk, Lerk and Snap. Our estimate of \begin{document}$ H_0 $\end{document} is remarkably consistent with various recent Planck Collaboration studies that utilize the ΛCDM model. According to our study, power law cosmology within the context of \begin{document}$ f(R,G) $\end{document} gravity provides the most comprehensive explanation of the important aspects of cosmic evolution.
Geometric Constraints via Page Curves: Insights from Island Rule and Quantum Focusing Conjecture
Ming-Hui Yu, Xian-Hui Ge
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Abstract:
Exploring the inverse problem tied to the Page curve phenomenon and island paradigm, we investigate the geometric conditions underpinning black hole evaporation where information is preserved and islands manifest, giving rise to the characteristic Page curve. Focusing on a broad class of static spherical symmetry black hole metrics in asymptotically Minkowski or (anti-)de Sitter spacetimes, we derive a pivotal constraint: the second derivative of blacken factor \begin{document}$ f^{\prime \prime}(r_h)<\frac{6 \kappa A^{\prime}(r_h)}{cG_N} $\end{document} for which the island exists and reproduce the Page curve. On the other hand, starting from the quantum focusing conjecture theory, we obtain another constraint on the blacken factor: \begin{document}$ f^{\prime \prime}(r_h)< \frac{6 \kappa^2 r_h A^{\prime}(r_h) e^{2\kappa r_{\star}(b)} }{cG_N f(b)} $\end{document} that the theory can be satisfied. In particular, by studying these two constraints, we find that a common properties. Specifically, we reveal that a universally criterion – manifested in the negativity of the second derivative of \begin{document}$ f(r) $\end{document}, i.e. \begin{document}$ f^{\prime \prime} (r)<0 $\end{document}, in proximity to the event horizon where \begin{document}$ r \sim r_h+ {\cal O} (G_N) $\end{document}, ensures the emergence of Page curves and follows the quantum focusing conjecture in a manner transcending specific theoretical models. Finally, we argue that the negativity of the second derivative of the blacken factor \begin{document}$ f(r) $\end{document} near the event horizon strongly indicates negative heat capacity, which implies that black holes with a negative heat capacities must have islands and satisfy the quantum focusing conjecture.
核理论
Investigation of decay mechanisms and associated aspects of exotic Nobelium isotopes using the Skyrme energy density formalism
Shubhpreet Kaur, Raj Kumar, Manoj K. Sharma
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Abstract:
Background: The search of the heavier elements has yielded many surprises and enhanced our knowledge in the direction of nuclear synthesis and associated dynamical aspects. Although new elements and their associated isotopes have been synthesized, the amount of information with the Z ≥ 102, remains somewhat scarce. Further, in the domain of transfermium elements, the nuclear shell structure is of significant relevance for ensuring nuclear stability. Hence, the shell effects become indispensable for such nuclei. Purpose: Persistent experimental and theoretical endeavors have been conducted to examine the reactions induced by heavy ions and the subsequent decay mechanisms in the realm of superheavy mass. In addition, the region of transfermium elements is itself of great interest because of the neutron / proton shell effects. Here, Our objective is to analyze the subsequent decay mechanisms of nuclides of Z = 102 nucleus, i.e. 248No* and 250No*. Methods: An extensive study is conducted using the dynamical cluster-decay model (DCM) based on Quantum Mechanical Fragmentation Theory (QMFT). The focus is on investigating compound nucleus (CN) and non-compound nucleus (nCN) mechanisms, including fusion-fission (ff), Quasi fission (QF), and fast fission (FF). The specific isotopes of interest are 248No* and 250No*, with attention given to the role of centre of mass energy \begin{document}$ (E_{c.m.}) $\end{document} and angular momentum \begin{document}$ (\ell) $\end{document}. The nuclear interaction potential is derived using the Skyrme energy density formalism (SEDF) with the GSkI force parameters. The capture cross-sections are calculated using the \begin{document}$ \ell $\end{document}-summed Wong Model. The determination of the probability of compound nucleus formation (PCN) uses a function that is dependent upon the center of mass energy. The lifetimes of the fusion-fission (ff) quasi fission (QF) channels are also investigated. Results: Here, CN and nCN decay mechanisms for two isotopes of Z=102 nobelium are analysed over the range of centre-of-mass \begin{document}$ (E_{c.m.}) $\end{document} by taking into account the quadrupole deformation \begin{document}$ (\beta_2) $\end{document} and optimum orientations \begin{document}$ (\theta_{opt.}) $\end{document} of decaying fragments. The fragmentation potential, preformation probability, neck length parameter and reaction cross-sections are explored. Further, the calculations are done for PCN to determine the mechanisms of decay of 248No* and 250No* isotopes. The fusion-fission lifetimes and quasi fission lifetimes are compared with the dinuclear system (DNS) approach. Conclusions: Among the considered isotopes of Z = 102 i.e., 248No* formed in 40Ca + 208Pb reaction and 250No* via to different entrance channels 44Ca+206Pb and 64Ni+186W show asymmetric fragmentation with the effect of \begin{document}$ \beta_2 $\end{document} deformation at the energies beyond the Coulomb barrier. It has been noted, the nCN (QF,FF) decay mechanisms compete with CN fission channels. The calculations based on DCM show a strong correlation with the experimental data. The most probable fragments such as 122Sn and 128Te are observed near the magic shell closure Z = 50 and N = 82. As the excitation energy increases, the lifetime of fusion-fission and quasi fission decreases.

ISSN 1674-1137 CN 11-5641/O4

Original research articles, Ietters and reviews Covering theory and experiments in the fieids of

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